Photographic-printing process



UNITED STATES PATENT ornce.

JOHN EDWARD THORNTON, OF WEST HAMPSTEAD, LONDON, ENGLAND, ASSIGNOR TO JOHN OWDEN OZBRIEN, OF MANCHESTER, ENG-LAND.

PHOTOGRAPHIC-PBINTING PROCESS.

No Drawing. Original application filed March 21,

1916, Serial no. 85,702. Divided and. this application filed July 8, 1919. Serial No. 309,426.

To all whom it may concern Be it known that I, JOHN EDWARD THORN- TON, a British subject, residing at West Hampstead, London, England, have invented certain new and useful Improvements in and Relating to Photographic-Printing Processes, of which the following is a specification.

This invention relates to the production of kinem atograph films.

The object of the invention is to prepare a printing belt or belts by which transparent kinematograph films of indefinite length can be produced, by mechanical printingof the pictures thereon with applied inks or colours as distinct from printing photographically with sensitive chemical media acted upon by light and as distinct from applying colour to a photographically printed series of pictures.

The original picture film of indefinite length is photographed in the ordinary way and fromthis the one or more printing belts" are prepared by any of the processes known in photo mechanical printing as intaglio in which a series of fine indentations or pits are formed to receive the ink or colour and may be termed ink wells or pits and from which the ink or colour is transferred to the surface of the transparentkinematograph film of indefinite length.

Photo mechanical follows :The actual operation of printing requires neither the use ofa sensitive surface nor the action of light, nor subsequent development. Instead of such methods printing is efiected by mechanical pressure ofthe film against a plate (in the form of a our instead of a sensitive salt;

continous' belt) which has been prepared with a series of images by one of the photo mechanical processes.

The medium used to form the image is therefore a printing or applied ink'or col- Various kinds of inks or'colours can be used according to the particular type of engraved or other printing plate (herein termed printing belt) used.

. prepare a strip or band of copper, steel, brass, aluminum or other metal, or a strip of gelatine, the gelatine being on a supporting base, or a strip of celluloid with a coating of printing is defined as gelatine or other colloid prepared with a sensitive surface in any of the methods well known for photo mechanical printing to repfiive an impression of the original picture The prepared strip whichv is to form the printing belt is perforated or notched along its margins to correspond precisely with the chanical printing surface (hereinafter referred to as a printing belt) comprising a number of fine indentations or pits to .contaln and transfer ink or colour, by photographically forming thereon from the original picture film through a screen as hereinafter described. The gradations of light and shade are produced by depositing varying quantities of ink by the varying size or capacity of the ink pits or wells either by varying the size or area thereof whilst maintaining a uniform depth or varying the depth whilst maintaining a uniform area, or by varying both area and depth and also by yarying their distance apart.

The printing belt is engraved in intaglio by the processes known as photogravure, intaglioor reversed half tone. The images for this process are produced by the same means (merely reversed) as used for preparing an engraved relief belt. Inkcor colour is applied to the intaglio image by a plush roller that completely fills the indentations or pits, and the surplus is wiped ofi" the surface of the belt by a scraper, leaving the indentations filledto the top with ink, which is afsion a high degree of 'tint is reached and desirable or special effects for harmonizing harshness or other defects becomes practicable. Or one of such printing beltsmay be used for printing say a light shade or tone of blue or a greenish blue, and another Photography published in of the printing for printing a deep blue or a purple blue to give better effect to the colours in the p1cture. This mode of operation is regarded as of special importance in relation to originals produced by the two-colour process.

The printing belt is made of a strip of continuous indefinite length of metal, celluloid or other material with the pictures etched thereon in intaglio by Well known methods, or any one of the published and current procedures for making an intaglio printing surface. a A process for forming a printin surface of actual hardened gelatine is the eimtype of Husnik which is briefly described on pages 330 and 331 of Uassels Cyclopaedz'a of 1912, and further a description is given in Husniks British specification No. 37 of 1887. To obtain the most satisfactory results by the Leimtype process certain improvements and modifications are desirable and these as hereinafter described must be regarded as a part of thepresent invention. The film base is a flexible band of metal, celluloid or other material grooved or perforated to promote the adhesion of the gelatine with which it is coated, this coating being on one side or both, and the gelatine having been sensitized and printed and treated in accordance with the Husnik method gives a grained typographic surface, but when an intaglio surface is required the exposure should be under a lined or grained diapositive.

A printing belt having a base of celluloid is coated with a sensitized resist (as for example bichromated fish glue) similar to that used on metal for ordinary process work. I print upon it from the original picture fihn and after exposure, followed by washing out in the usual way, the-celluloid is etched by an air blast or a sand blast charged wit-h a solvent of celluloid such for example as amyl-acetate.

In the preparation of the printing belts when printing through the screen it is desirable that the screen should be moved slightly-relatively to the belteither laterally or longitudinally or both after each individual picture is exposed so that the indentations or pits in the printing surface belt and subsequently the dots or points or lines printed therefrom upon the kinematograph film will not fall in the same place in the successive pictures and so owing to the rapidity of projection and the rsistence of vision such dots or points wi 1 not be visible on the enlargement when projected upon a sheet or screen, the

pictures appearing as a full tone grainless picture.

The kinematograph fiZm.The strip or. film upon which the pictures are to be printed from the printing belts to produce the and intensifying parts of each image bly be t scribed any suitable printing ink or colour may be employed that is'adapted to the particular form of printing belt and the surface of the film upon which the print is-to be made.

The printing may be done by applying the ink to the printing belts by any well known printing method such as by a roller, and removing the excess by a doctor or knife. The printing belts with perforations along the margins in which re istering pins can operate and the film a so similarly perforated along the margins are drawn together between rollers or pressin surfaces by which contact or pressure will e applied picture by picture. Sprocket teeth or claws are fitted to draw the tWo through the machine in correct register.

What I claim as my invention and desire to protect byLetters Patent is 1. A photo mechanical printing belt of continuous indefinite length for the production of continuous indefinite lengths of transparent kinematograph positive fihn pictures, provided with perforations in the 'margins accurately spaced and a series of printing clichs formed on the surface and the gradation of a photograph, the clich consisting of a large number of broken tone markings comprising intaglio pits forming inkwells, and the gradation of image being formed by making the said pits of varying capacity per unit of areaso that the are capable of depositing varying quantifies of ink, and thus formin a series of printed images of full gra-datlon by the agency of of applied ink and pressure. p

2. series of photo mechanical printing belts of continuous indefinite length for producing continuous indefinite lengths of transparent kinematograph positive films as in claim 1, for printing the main part. of each image by one intaglio. printing belt,

printing from another intaglio printing or belts, the corresponding parts of each image of the series bein different in the quantity of ink deposit for each belt, and

requiring the printing from all belts in succession to complete the series of images and to diflerently intensify each image of the series. T

3. A series of perforated photo mechanical printing belts for producing continuous indefinite lengths of kinematograph positive films by means of half tone intaglio ink pits of varying capacity per unit of area, as in claim 1, the said ink pits having their incidence varied in relation to the particular part of the picture image upon every printing belt of the series, in order that the grain of the picture may be obliterated by the successive printings, and thus form a series of full tone grainless film pictures by applied ink and pressure and superimposed printings,

i. A series of perforated photo mechanical printing belts for producing continuous lengths of kinematograph positive prints in multi-colour heliochrome. by means of half tone intaglio ink pits of varying capacity per unit of area as in claim 1, each colour of the composite heliochrome being formed upon a separate belt, which colors are subsequently printed on to the film by super imposed printing, and by applied ink and pressure, to produce complete heliochrome continuous positive films.

5. A series of perforated photo mechanical printing belts for producing continuous lengths of kinematograph positive prints in multi-colour heliochrome, by means of half tone intaglio ink pits of varying size and area as in claim 1,the composite heliochrome being split into a plurality of printings of each colour and each being printed from a difi'erent belt in which the ink pits have their incidence varied in relation to the same particular part of the picture image,

in order that the grain of one printing may be obliterated by the second printing of the same section of the picture, with the object of producing, when the remaining colours of the image series have been similarly split and applied, a series of grainless full tone heliochrome kinematograph positive film pictures, by applied ink and pressure and superimposed printings.

6. A continuous printing belt as in claim 1, having its printing cliches produced by intaglio methods, in a-series of ink-holding pits of varying capacity per unit of area depth, which receive varying quantities of ink according to their varying capacity, and yield it to an absorbent film surface by means of applied pressure. I

7. A continuous intaglio printing belt, as in claim 6, having its surface grooved to promote adhesion to the clichs formed on its face and prevent their tearing ofi' during inking and printing.

8. A continuous printing belt for direct printing on to a continuous kinematograph film as in claim 6, prepared with pit-like intaglio images by the improved Leimtype method substantially as described.

9. A photo mechanical printing belt of 'continuous indefinite length provided with perforations in the margins and having formed thereon by photo-chemical means a series of printing clichs having pictures arranged in succession longitudinally thereon, each composed of a large number of -intaglio ink pits, the gradation of each image being formed by making the said ink pits of varying capacity to render them capable of depositing varying quantities of ink to form pictures, in the form of a continuous series upon a continuous indefinite length of kinematograph film, and the ink pits in each succeeding cliche of the series staggered in relation to those of the adjacent clichs. v

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JOHN EDWARD THORNTON.

Witnesses:

J. OWDEN OBRIEN, V. J. A. HORSWORTHY. 

